Illuminating device incorporating optical lens

ABSTRACT

An illuminating device includes a light source module for emitting light and an optical lens for adjusting the light. The light source module includes a reflecting unit and LEDs. The reflecting unit includes strip-shaped grooves each extending along a first direction. The LEDs are mounted on the reflecting unit in the grooves. The optical lens includes an array of lens units each including a main body, a light diverging portion and a light converging portion. The light diverging portion is for expanding a light field of the LEDs along the first direction. The light converging portion is for compressing the light field along a second direction. The reflecting unit is for further compressing the light field along the second direction.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application is a divisional application of patentapplication Ser. No. 12/168,776, filed on Jul. 7, 2008, entitled“OPTICAL LENS AND ILLUMINATING DEVICE INCORPORATING THE SAME”, assignedto the same assignee, and disclosure of which is incorporated herein byreference in its entirety.

BACKGROUND

1. Technical Field

The disclosure generally relates to illuminating devices, andparticularly to an illuminating device incorporating an optical lens,which can improve utilization rate of light emitted from light emittingdiodes (LEDs).

2. Description of Related Art

With the continuing development of scientific technology, LEDs have beenwidely used in illumination devices to substitute for conventional coldcathode fluorescent lamps (CCFL) due to their high brightness, longlife-span, and wide color gamut. Relevant subject matter is disclosed inan article entitled “Solid State Lighting: Toward SuperiorIllumination”, published in a magazine Proceedings of the IEEE, Vol. 93,No. 10, by Michael S. Shur et al. in October, 2005, the disclosure ofwhich is incorporated herein by reference.

Conventional illuminating devices incorporating LEDs generally generatebutterfly-type light fields or diffusion-type light fields. Referring toFIG. 14, a diffusion-type light field is shown. The diffusion-type lightfield is substantially circular. In other words, a part of the lightfield along an x-direction is substantially the same as a part of thelight field along a y-direction. However, this type of light field isnot always required in our daily life, such as in a street lamp, whichhas a strip-type light field requirement. If the diffusion-type lightfield is applied in the street lamp, part of light will be lost, whichdecreases utilization rate of the light emitted from the LEDs.

What is needed, therefore, is an optical lens and an illuminating deviceincorporating the optical lens, which can improve utilization rate ofthe light emitted from LEDs.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present illuminating device can be better understoodwith reference to the following drawings. The components in the drawingsare not necessarily drawn to scale, the emphasis instead being placedupon clearly illustrating the principles of the present illuminatingdevice. Moreover, in the drawings, like reference numerals designatecorresponding parts throughout the several views.

FIG. 1 is an isometric, schematic view of an illuminating device, inaccordance with a first embodiment of the disclosure.

FIG. 2 is an isometric view of an optical lens of the illuminatingdevice of FIG. 1, but viewed from another aspect.

FIG. 3 is an isometric view of a lens unit of the optical lens of FIG.2.

FIG. 4 is a graphic view showing a light field generated by theilluminating device of FIG. 1.

FIG. 5 is an isometric, schematic view of an optical lens, in accordancewith a second embodiment of the disclosure.

FIG. 6 is an isometric view of a lens unit of the optical lens of FIG.5.

FIG. 7 is a cross-sectional view of the lens unit of FIG. 6, taken alongline VII-VII thereof.

FIG. 8 is a cross-sectional view of the lens unit of FIG. 6, taken alongline VIII-VIII thereof.

FIG. 9 is a graphic view showing a light field generated by the opticallens of FIG. 5.

FIG. 10 is an isometric, schematic view of a lens unit, in accordancewith a third embodiment of the disclosure.

FIG. 11 is an isometric, schematic view of a lens unit, in accordancewith a fourth embodiment of the disclosure.

FIG. 12 is an isometric, schematic view of an illuminating device, inaccordance with a fifth embodiment of the disclosure.

FIG. 13 is a graphic view showing a light field generated by theilluminating device of FIG. 12.

FIG. 14 is a graphic view showing a diffusion-typed light field inaccordance with a related art.

DETAILED DESCRIPTION

Referring to FIG. 1, an illuminating device 1 in accordance with a firstembodiment of the disclosure includes an optical lens 10 and a lightsource module 80 emitting light towards the optical lens 10.

The optical lens 10 is used to adjust the light so that the light cangenerate a light field in a desired shape. The optical lens 10 includesan array of lens units 11. The light source module 80 includes a circuitboard 83 and a plurality of LEDs 84 mounted on the circuit board 83. TheLEDs 84 have one-to-one corresponding relationships with respect to thelens units 11 of the optical lens 10.

Referring to FIG. 2, the optical lens 10 is viewed from another aspect.Each lens unit 11 includes a main body 101. The main body 101 has alight incident surface 110 and a light emitting surface 112 opposite tothe light incident surface 110. The light emitted from the LEDs 84enters into the lens units 11 from the light incident surface 110, andexits out of the lens units 11 from the light emitting surface 112.

Referring to FIG. 3, each lens unit 11 further includes a lightdiverging portion 114 for diverging the light emitted from the LEDs 84along an x-direction, and a light converging portion 116 for convergingthe light emitted from the LEDs 84 along a y-direction. An angle αdefined between the x-direction and the y-direction is 90 degrees.

In the present embodiment, the light diverging portion 114 is formed onthe light incident surface 110. The light incident surface 110 is aconcave curved surface. In the present embodiment, the concave curvedsurface is a portion of an inner side surface of a cylinder. The lightincident surface 110 extends along the y-direction and serves as thelight diverging portion 114. Due to the configuration of the lightdiverging portion 114, the light diverging portion 114 enables the lightpassing therethrough to radially deflect from the x-direction. In otherwords, the light is deflected from a center towards two sides of thelight incident surface 110. As a result, a part of the light field alongthe x-direction generated by the LEDs 84 is expanded after the lightpasses through the light diverging portion 114.

The light converging portion 116 is formed on the light emitting surface112. The light emitting surface 112 has a convex curved surface. In theembodiment, the convex curved surface is a portion of an outer sidesurface of a cylinder. The light emitting surface 112 extends along thex-direction and serves as the light converging portion 116. Due to theconfiguration of the light converging portion 116, the light convergingportion 116 enables the light passing therethrough to deflect from twosides towards a center of the light emitting surface 112. As a result, apart of the light field along the y-direction generated by the LEDs 84is compressed after the light passes through the light convergingportion 116.

Referring to FIG. 4, the light field generated by the illuminatingdevice 1 is shown. An illuminating length of the light field along thex-direction is greater than that of the light field along they-direction. An illuminating intensity of the light field along thex-direction is greater than that of the light field along they-direction. Accordingly, the illuminating device 1 can be applied in anapplication that requires a strip-type light field, such as in a streetlamp, so as to improve the utilization rate of the light emitted fromthe LEDs 84.

A curvature of the light diverging portion 114 can be changed, so as toobtain a desired illuminating length and intensity of the light fieldalong the x-direction. A curvature of the light converging portion 116can be changed to obtain a desired illuminating length and intensity ofthe light field along the y-direction. As a result, the illuminatingdevice 1 can satisfy different requirements merely by changing thecurvatures of the light diverging portion 114 and the light convergingportion 116.

In addition, the configuration of the light diverging portion 114 is notlimited to a portion of an inner side surface of a cylinder along they-direction. If desired, the light diverging portion 114 can be otherconcave curved surfaces, such as a portion of a side surface of a cone,a portion of a spherical surface and so on. The configuration of thelight converging portion 116 is not limited to a portion of an outerside surface of a cylinder along the x-direction. If desired, the lightconverging portion 116 can be other convex curved surfaces, such as aportion of a side surface of a cone, a portion of a spherical surfaceand so on.

Furthermore, the angle α defined between the x-direction and they-direction can be an acute angle, such as 45 degrees, 60 degrees and soon.

Moreover, the light diverging portion 114 can be formed on the lightemitting surface 112, and the light converging portion 116 can be formedon the light incident surface 110.

Referring to FIGS. 5 to 8, an optical lens 20 in accordance with asecond embodiment of the disclosure is shown. The optical lens 20 issimilar to the optical lens 10 in the first embodiment. In the presentembodiment, the light emitting surface 212 is a planar surface. Thelight diverging portion 214 and the light converging portion 216 of thelens unit 21 both are formed on the light incident surface 210. Namely,the light incident surface 210 is a composite curved surface of theconcave curved surface along the y-direction and the convex curvedsurface along the x-direction. A height of the light incident surface210 at a center thereof is less than that of the light incident surface210 at two sides thereof along the x-direction. A height of the lightincident surface 210 at the center thereof is greater than that of thelight incident surface 210 at the two sides thereof along they-direction. The principle of the light compression along thex-direction and the light expansion along the y-direction in the presentembodiment is substantially the same as that in the first embodiment.

Referring to FIG. 9, the light field generated by the optical lens 20 isshown. An illuminating length of the light field along the x-directionis greater than that of the light field along the y-direction. Anilluminating intensity of the light field along the x-direction isgreater than that of the light field along the y-direction. Accordingly,the optical lens 20 can be applied in an application that requires astrip-type light field.

Referring to FIG. 10, a lens unit 31 in accordance with a thirdembodiment of the disclosure is shown. The lens unit 31 is similar tothe lens unit 11 in the first embodiment. In the present embodiment, thelight converging portion 316 formed on the light emitting surface 312 ofthe main body 301 includes a plurality of recesses 318 defined in thelight emitting surface 312 of the main body 301. The recesses 318 areparallel to each other along the x-direction, and symmetricallydistributed on the light emitting surface 312 with respect to a centralline of the light emitting surface 312. The recesses 318 have a widthgradually decreased from a center towards two sides of the lightemitting surface 312 along the y-direction.

Each recess 318 has a slanted top surface 3182 and a vertical sidesurface 3184 connected to a top surface 3182 of an adjacent recess 318.The two top surfaces 3182 of the two recesses 318 adjacent to the centerof the light emitting surface 312 are connected with each other. The topsurface 3182 is an inclined planar surface, which has a predeterminedslope. A slope of the top surface 3182 gradually increases from thecenter towards the two sides of the light emitting surface 312 along they-direction. Alternatively, the top surface 3182 of each recess 318 canbe a curved surface, which has a predetermined curvature.

In the lens unit 31, the recesses 318 of the light converging portion316 are parallel to each other and distributed on the light emittingsurface 312, and the top surface 3182 of each recess 318 is an inclinedplanar surface or a curved surface, whereby the light converging portion316 enables the light passing therethrough to deflect towards the centerof the light emitting surface 312 along the y-direction. As a result,the light field along the y-direction generated by the LEDs 84 iscompressed after the light passes through the light converging portion316.

Referring to FIG. 11, a lens unit 41 in accordance with a forthembodiment of the disclosure is shown. The lens unit 41 is similar tothe lens unit 31 in the third embodiment except that a light divergingportion 414 is provided on the light incident surface 410. In thepresent embodiment, the light diverging portion 414 formed on the lightincident surface 410 of the main body 401 includes a plurality ofprotrusions 419 protruding outwardly and upwardly from the lightincident surface 410 of the main body 401. The protrusions 419 areparallel to each other along the y-direction, and are symmetricallydistributed on the light incident surface 410 with respect to a centralline of the light incident surface 410. The protrusions 419 have a widthgradually decreasing from a center towards two sides of the lightincident surface 410 along the x-direction.

Each protrusion 419 has a slanted bottom surface 4192 and a verticalside surface 4194 connected to the bottom surfaces 4192 of an adjacentprotrusion 419. The two bottom surfaces 4192 of the two protrusions 419adjacent to the center of the light incident surface 410 are connectedwith each other. The bottom surface 4192 is an inclined planar surface,which has a predetermined slope. A slope of the bottom surface 4192gradually increases from the center towards the two sides of the lightincident surface 410 along the x-direction. Alternatively, the bottomsurface 4192 of each protrusion 419 can be a curved surface, which has apredetermined curvature.

In the lens unit 41, the protrusions 419 of the light diverging portion414 are parallel to each other and distributed on the light incidentsurface 410 along the y-direction, and the bottom surface 4192 of eachprotrusion 419 is an inclined planar surface or a curved surface,whereby the light diverging portion 414 enables the light passingtherethrough to radially deflect along the x-direction. As a result, thelight field along the x-direction generated by the LEDs 84 is expandedafter the light passes through the light diverging portion 414.

Referring to FIG. 12, an illuminating device 5 in accordance with afifth embodiment of the disclosure is shown. The illuminating device 5is similar to the illuminating device 1 in the first embodiment. In thepresent embodiment, the light source module 50 includes a reflectingunit 51 and a plurality of optical modules 52 mounted on the reflectingunit 51.

The optical module 52 includes a strip-shaped circuit board 53 and aplurality of LEDs 54 mounted on the circuit board 53. The LEDs 54 haveone-to-one corresponding relationships with respect to the lens units 11of the optical lens 10. The reflecting unit 51 includes a plurality ofparallel and strip-shaped grooves 57 along the x-direction. Each groove57 has an inverted trapeziform transverse section. Each groove 57 iscooperatively enclosed by a bottom wall 570 and two sidewalls 572 (onlyone sidewall is labeled). The two sidewalls 572 are disposed opposite toeach other. Each sidewall has a reflecting capability. Each opticalmodule 52 is received in one corresponding groove 57, with the circuitboard 53 of the optical module 52 abutting against the bottom wall 570of the corresponding groove 57.

The light emitted from the LEDs 54 is reflected by the sidewalls 572 ofthe grooves 57 to deflect towards a center of the light source module 50along the y-direction, and then towards the optical lens 10. As aresult, the light field along the y-direction generated by the LEDs 54is further compressed after the light passes through the optical lens10.

Referring to FIG. 13, the light field generated by the illuminatingdevice 5 is shown. An illuminating length of the light field along they-direction is further compressed compared with the light field shown inFIG. 4. In addition, a glare phenomenon is further eliminated.

It is believed that the disclosure and its advantages will be understoodfrom the foregoing description, and it will be apparent that variouschanges may be made thereto without departing from the spirit and scopeof the invention or sacrificing all of its material advantages, theexamples hereinbefore described merely being preferred or exemplaryembodiments of the invention.

1. An illuminating device comprising: a light source module for emitting light, the light source module comprising a reflecting unit and a plurality of light emitting diodes (LEDs) mounted on the reflecting unit, the reflecting unit comprising a plurality of strip-shaped grooves each extending along a first direction, the LEDs being mounted on the reflecting unit in the grooves; and an optical lens configured for adjusting the light emitted from the light source module, the optical lens comprising an array of lens units, each lens unit comprising a main body, a light diverging portion and a light converging portion, the main body comprising a light incident surface and a light emitting surface opposite to the light incident surface, the light diverging portion being configured for expanding a light field along the first direction, the light converging portion being configured for compressing a light field along a second direction, the light diverging portion and the light converging portion being formed on at least one of the light incident surface and the light emitting surface.
 2. The illuminating device of claim 1, wherein the grooves of the reflecting unit are parallel to each other and distributed along the second direction.
 3. The illuminating device of claim 2, wherein each groove has an inverted trapeziform transverse section, each groove being cooperatively defined by a bottom wall and two sidewalls disposed opposite to each other.
 4. The illuminating device of claim 3, wherein the sidewalls of the grooves each have a reflecting capability, the light emitted from the light source module being reflected by the sidewalls of the grooves to deflect towards a center of the light source module along the second direction so that the light field along the second direction being further compressed.
 5. The illuminating device of claim 1, wherein the light diverging portion is a concave curved surface, and the light converging portion is a convex curved surface.
 6. The illuminating device of claim 5, wherein the concave curved surface is a portion of an inner side surface of a cylinder, and the convex curved surface being a portion of an outer side surface of a cylinder.
 7. The illuminating device of claim 5, wherein the concave curved surface is a portion of a side surface of a cone or a portion of a spherical surface.
 8. The illuminating device of claim 5, wherein the convex curved surface is a portion of a side surface of a cone or a portion of a spherical surface.
 9. The illuminating device of claim 5, wherein the light diverging portion is formed on one of the light incident surface and the light emitting surface, the light converging portion being formed on the other one of the light incident surface and the light emitting surface.
 10. The illuminating device of claim 1, wherein the LEDs have one-to-one corresponding relationships with respect to the lens units of the optical lens.
 11. The illuminating device of claim 1, wherein a predetermined angle is defined between the second direction and the first direction.
 12. The illuminating device of claim 11, wherein the first direction is perpendicular to the second direction. 